1. Field of the Invention
The present invention relates to the field of computer animation and, in particular, to 3D graphics user interface (UI) affordances based on behind-the-scenes simulation.
2. Description of the Related Art
Computer-based animation often involves scenes that include both static and dynamic objects. Main characters and movable objects are modeled as dynamic objects. Items that do not move in the scene, such as set elements, are modeled as static objects. Typically, the animator places such static objects manually, and the static objects remain in place during the simulation of the animated scene. In some cases, placing such static objects involves building a complex geometric model with a large number of individual elements. For example, an animator could place a large number of leaves or debris on a floor or grassy area, where the leaves remain in place during the animated scene. To improve aesthetic quality, the individual elements should be placed in such a manner that the elements have believable geometric contact. In the example, the animator would place leaves such that, when the leaves settle into place, the leaves rest against the floor or ground and against each other, such that the leaves would look visibly correct. That is, the leaves should not intersect or pass through each other.
One possible approach for achieving the desired visual aesthetic is for the animator to manually place each object in the scene. For example, the animator could place each leaf, one at a time, until all leaves are placed in the scene. One drawback to this approach is that the time to place all the elements is labor-intensive, particularly in a scene with hundreds or thousands of elements to place. As a result, production time and cost increase with the complexity of the static objects within each scene. Alternatively, the animator may choose to place fewer objects in each scene, reducing the artistic freedom to produce the desired look for various computer-generated set designs.